Half to augusta h



N. W. BRNETT.

l STEAM ENGINE. A

Patented Nov.l 20, 1894.v

l (No Model.)

' NITED `STATES NATHAN w.

PATENT Fries..

HALF TO AUGUSTA H. LINDSAY, OFSAME PLACE.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. v529,581, dated November 20, 1894.

l Application filed August 15, 1894. Serial No. 520,379. (Nonlodel.)

To au whom, it may concern.-

Be it known that I, NATHAN W. BARNETT, a citizen of the United States of America, residing at Monaca, in the county of Beaver and State of Pennsylvania, have invented c ertain neit7 and useful Improvements-in Steam- Engines, of which the following isa specilication.

This invention relates to improvements in steam-engines. v

It has for its object to provideimproved means for the exhaust of steam by means of valves in a double or two headed piston, and a chamber between the piston heads, to a suitable exhaust pipe, after it has performed its work.

A further object is to provide such an im,-

proved exhaust as will result in a maximum amount of power for the amount 'of steam used, and to prevent loss from the reaction of steam not exhausted or defectively exhausted, such as has been encountered in engines heretofore used.

For a full and clear understanding of my invention, reference is to be had to theaccompanying drawings wherein corresponding letters indicate like parts in the several Views, and in which- Figure lis a central, longitudinal sectional View of a cylinder illustrating a double headed piston with a chamber between the piston in communication with an exhaust pipe, connected valves in the piston heads, and springs at the ends of the cylinder. Fig.

2 is an outward end view of one of the pis.

toil heads, being similarly constructed. But one head is shown. Fig. 3- is a view of an open frame guide-way.

In the drawings, Arefers to a cylinder of a steam engine of ordinary construction, excepting the piston heads and -exhaust mechanism, parts being broken away for better illustration.

B, B', are twopiston heads suitably and 4centrally mounted on a piston rod B, forming a chamber C between said heads. f D is an exhaust opening in the bottom of the cylinder near the center Of the same and at all times in open communication withchamber C, as shown.

In the piston heads B, B', underneath the piston rod B are two circular openings b, b',-

forming, on the outside of the heads, valve seats G adapted to receive valves Eand Fon the ends of a connecting rod G and of such distance apart that when one valve contacts with its seat, the other valve is raised off its seat, as shown in Fig. l. .The outer ends of the valves have enlarged and flatsurt'aces E' and outward projections E2 thereon in line with rod Gfor purposes hereinafter described.

H are open frame guide-ways, see Fig. 3,of

suitable form secured td the inner surfaces ofthe piston heads over the openings b, b', therein and in which rod Gis guidedin its play back and forth in the opening and closing of the valves, as hereinafter explained.

I, I, are depending steel blade springs having upper andoutwardly curved ends bolted or otherwise secured to the cylinder heads near their centers, as shown. Thelower ends of these springs are in direct linewith rod G in the piston heads. When steam is admitted, in the ordinary way, at` one end of the cylinder, it closes by 'its pressure on the outward surface thereof, the Valve in the piston head nearer that end of the cylinder, and, at the same time, raises the valve in the other head of the cylinder off its seat by means of rod G. As soon as the double piston is forced to the end of the cylinder, a projection E2 on the valve nearer that cylinder head contacts with one of the springs I. The impact and the elasticity of the spring are sufficient to reverse the position of thevalves E, F, thereby opening the valve farther from this cylinder head and forming an opening for the spent Iclaim, and desire to secure byLetters Pat-` ent, is-

The combination in an engine, of a cylinder having springs secured to the inner surfaces of its heads, a piston rod, two piston IOO heads secured on said rod, a chamber between said heads, Valves in the piston heads, a rod connecting said valves, open framed gnide ways foil the latter rod on the inner surfaces of the piston heads, an exhaust pipe in the cylinder in communication with said chamber, projections on the valves to Contact With the springs in the cylinder t0 operate the valves when steam is admitted to the cylinder, as and for the purposes set forth. A :o

In testimony whereof I ax my signature in presence of two witnesses.

NATHAN W. BARNETT. Witnesses:

JOHN E. SCHMIDT, n JOHN MITCHELL. 

